The Applicant's French patent FR-A-No. 2140782 relates to a regulator apparatus of this kind which has one or more sensor units for one or more variables related to the load flow rate, in particular noise generated by the apparatus, together with means for maintaining the load flow rate at a predetermined value as a function of the readings of the sensor unit.
Indeed, it is known that noise generated by a crusher is very loud when the crusher is almost empty and decreases very rapidly as the material to be crushed is fed in, and then tends asymptotically towards a minimum value. By regulating the crusher to a low noise level, a zone of operation is obtained in which the power consumed decreases as the quantity of material being crushed increases and the efficiency of the crusher is high.
However, regulating the load flow rate does not necessarily give the best operating conditions when the properties of the material to be crushed (grain size, friability, dampness, etc) are variable. In such a case, there is a danger of not obtaining optimum efficiency nor constant quality of the crushed material which may then be sometimes insufficiently crushed or on the contrary it may be excessively crushed.
The present invention aims to remedy these drawbacks and to provide a method and apparatus for regulating the operation of a crusher which is not very sensitive to the modifications in properties of the material to be crushed and which crushes constantly with an efficiency close to the optimum value.
It also aims to avoid the crusher clogging by too much material to be crushed being let in, to reduce the wear of the crushing units as a function of the crushed material flow rate to a substantially minimum value, to make the crusher operate at a loading zone where it is the quietest, and to give it some degree of autonomy of operation in the case of momentary stoppage in the feed.